Xyloterus lineatus (Oliv.)From: Kolk A., Starzyk J. R., 1996: The Atlas of Forest Insect Pests Occurrence: Europe, Siberia, Japan, the USA, Canada. Host plants: Almost all coniferous species, but mainly spruces, firs and pines. Morphology: Adults are 2.5-3.6 mm long, cylindrical, robust. The underside of the body is dark or brown. Elytrae are dark brown with light stripes along. Elytral declivity is rounded. The head of males has a deep depression on frons and is covered with short hair. Eyes are divided on the upper and lower part. Eggs are white, 0.6x0.4 mm in size. Larvae are white, legless, characteristically banded, with the light brown head. Biology: Adults overwinter in litter and soil up to 3 cm in depth. They initiate flying in March, April or May, depending on weather. Adults of the sister generation fly in late-June - early-July. After mating, females first construct entering galleries 1 to 5 cm deep into the wood and later on make 1 to 4 egg galleries. The female lays 20-50 eggs singly into niches cut on both sides of egg gallery. Larvae hatched 6-14 days after oviposition feed on ambrosia fungi and construct ladder-like tunnels of up to 7 cm in length. The larval development lasts for 20-40 days. Several (7 to 10) days after pupation in galleries, young adults emerge and have 2 week maturation feeding on fungi mycelium. Damage: This species is one of the most serious technical pest of conifers. If abundant, beetles can infest also debarked wood. Infested trees can be easily detected by white boring flour coming out. Preventive measures: Removal of the timer from stands by early-March in lowlands and early-April in mountains. Insecticide treatment or watering of timber is also recommended. Storage of timber in sunny places is also helpful, if other methods can not be used. Control: Removal of all infested timber and trees before adult emergence. Insecticide treatment of newly-infested trees or their watering for the time not shorter than 4 weeks. The use of pheromone traps is also recommended. There should be 1 trap per 5 ha in low density populations, 1-2 traps per ha in moderate density, and 2-3 traps per ha in high density populations. Traps in each group should be placed in a distance of 2-5 m from each other. In wood yards, minimum 5 traps per ha is recommended if the population density is low, 10 traps per ha at medium population density, and 15 traps at high population density. Pheromone traps should be installed at least 30 m from logs, in shady places.
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Forest Pests: Insects, Diseases & Other Damage Agents |
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